A follow-up to the book "Unnatural Acts: Critical Thinking, Skepticism and Science Exposed!" by Robert Todd Carroll, creator of The Skeptic's Dictionary. The blog will offer irregular postings about cognitive biases, logical fallacies, and illusions.

Site Map

Monday, December 26, 2011

In science, an ad hoc
hypothesis is an assumption made in response to facts that are
inconsistent with a theory in order to prevent the theory from being
falsified. By extension, an ad hoc hypothesis is any assumption made to
save a claim from being refuted. What are often called ad hoc hypotheses
might better be referred to simply as rationalizations.One
of the more important ways of testing a scientific theory is to deduce
observations that should occur under specified conditions if the theory
is correct. An experiment may create those conditions and if the
predicted observations occur, the theory is said to be confirmed.
Experiments that confirm a theory should be replicable. If the predicted
observations do not occur and it is determined that the theory cannot
be correct if they do not, then the theory is falsified. Likewise, if
experiments fail to replicate confirmations and it is determined that
the theory cannot be correct if replication doesn't occur, then the
theory is said to be falsified. If a new fact is discovered that is
inconsistent with the theory, the fact must be accommodated. The theory
might be tweaked or it may be preserved by hypothesizing another fact
that would make the first fact consistent with the theory. Or, the fact
might prove the theory false.

___

When
William Hershel discovered the planet Uranus in 1781 by telescopic
observation, it was also discovered that the new planet’s orbit was
different from what it should have been according to Newton’s laws. The
orbit of Uranus was an anomaly: a phenomenon that apparently did not fit
with the Newtonian paradigm. Some scientists may have thrown up their
hands and said: “See, Newton was wrong! Hah!” Others may have offered
the ad hoc hypothesis that the anomalous orbit was caused directly by
God. Uranus has a different kind of orbit than the other planets because
God is working a miracle—suspending the laws of nature—perhaps to
demonstrate his power and existence to us. But most scientists set to
work to solve the puzzle. The simplest solution was to posit another
planet beyond the orbit of Uranus whose gravitational force was
affecting the planet’s orbit. This hypothesis could be independently
tested. Its size and orbit could be calculated based on how much it
perturbed the motion of Uranus. Thus was Neptune discovered. When the
math for Neptune’s orbit didn’t work in accordance with Newton’s laws,
it was proposed that still another planet awaited discovery. The object
known as Pluto gave astronomers the data to show that Neptune did, after
all, orbit in accordance with Newton’s laws. Both of these hypotheses
could be independently tested, albeit with some difficulty given the
state of knowledge and technology at the time.

___

When
Alfred Wegener proposed his theory of continental drift in 1912 against
the prevailing theory that the Earth was formed by cooling from a
molten state and contractions, he could not explain how continents move.
It was suggested that gravity was the force behind the movement of
continents, though there was no scientific evidence for this notion. In
fact, scientists could and did show that gravity was too weak a force to
account for the movement of continents. Alexis du Toit, a defender of
Wegener’s theory, argued for radioactive melting of the ocean floor at
continental borders as the mechanism by which continents might move.
“This ad hoc hypothesis added no increment of plausibility to Wegener’s
speculation,” wrote Stephen Jay Gould (Ever Since Darwin. W.W. Norton & Company.1979, p. 163).

___

George
Dillman claims that he and his top students can knock out people by
manipulating some sort of subtle energy called qi (chi or ch'i,
pronounced chee). When 8th degree black belt Leon Jay failed to move
Luigi Garlaschelli with qi, Dillman offered the following ad hoc
hypotheses. 1. Garlaschelli is a total non-believer and you must believe
you can be knocked out by qi for the power to work. 2. Garlaschelli
might have had one big toe pointing upward and the other pointing
downward. If so, the power won't work. 3. Maybe Garlaschelli wasn’t
knocked out because his tongue was "in the wrong position." While
Dillman's hypotheses seem like obvious rationalizations, they have the
merit of being empirically testable to a degree. Qi remains undetectable
by science's most refined measuring instruments, but we can at least
test the toe and tongue position claims. If the no-touch knockout
doesn't work even when the toes and tongues are aligned the way Dillman
wants them, we'll at least know that these hypotheses are false. On the
other hand, if Jay or Dillman knocked over Garlaschelli without touching
him when his toe and tongue were aligned, we'd have evidence in favor
of the qi hypothesis.

Sunday, December 18, 2011

In the concluding chapter of my book Unnatural Acts, I suggest that a good way to enhance critical thinking
would be to set a goal of studying various biases, fallacies, and
illusions that plague human thinking. I list 59 items worth
investigating. I hope this blog will help those choosing to study the
59 items, plus a few more.

After
this initial post, the blog will focus on specific cognitive biases,
illusions, or fallacies. The next post, for example, will be on ad hoc
hypotheses. But I thought I would introduce the blog with a case study
that would exemplify the dangers of following intuition and instinct
when making judgments. I view Unnatural Acts as an antidote to Malcolm Gladwell's Blink: The Power of Thinking Without Thinking. In Blink,
Gladwell argues that intuition or quick judgments can be just as
valuable as well thought out and time-consuming evaluations of data. In Unnatural Acts,
I try to make the case that while intuition works well enough in many
cases, for most important matters there is a much better chance of
making a fair and accurate judgment by doing the hard work of
collecting, analyzing, and evaluating data in an impersonal, reflective,
dispassionate way. Our natural instincts work well enough most of the
time, but occasionally we would be better off engaging in some unnatural
acts.

___

This
is a story about a mother trying to understand why her firstborn
suffered from a neurological disorder and after a short and miserable
existence died soon after his first birthday. It is the story of how a
powerful emotional experience affected her judgment to the point where
she became unable to see anything good in medicine or anything bad in
the anti-vaccination movement. I can't say I have all the details right,
but the general picture is clear enough from what information is
available about the case.

Stephanie Messenger says she wrote the children's book Melanie's Marvelous Measles
because vaccinations are ineffective, children should be taught to
embrace childhood disease, and getting a disease like measles helps
build the immune system naturally. Messenger explains her reasoning on
her website Nature Matters!, which she runs out of Queensland, Australia.

She tells us that she had her first child vaccinated twice by the time he was four months old. In the U.S., the recommended vaccine schedule
would include immunization against about a half dozen diseases during
an infant's first four months. Messenger writes of the initial
vaccination for her son:

Within
moments of my son receiving his immunisations he was screaming. This
continued for most of the day and when he wasn't screaming he was
crying. This was unusual as he was a very happy, placid baby, who was
already rolling over at 8 weeks and gooing and gahing at the first sight
of his mother. The doctor told me his reactions were 'normal' and he'd
be OK in a couple of days.

After
the first day he had almost recovered with only some irritability and
restlessness noticeable. As the weeks passed he continued to reach
milestones and all appeared OK.

It
would appear that her doctor was right. The infant stopped fussing and
"continued to reach milestones." Then he had his second round of
immunization:

At
4 months of age I dutifully took him for his next round of
vaccinations. This time he screamed louder and I could not console him
at all. I would breastfeed him, only to have him projectile vomit it
back up and still the screaming continued. He had never before vomited
at all, ever. After he had vomited 2 feeds I called the doctor and told
her what was happening and she said to stop breastfeeding and give him
juice only. He kept some of it down but still vomited often.

The
next day I called the doctor and told her I think the vaccines have
done this and she told me 'no, it's just a coincidence' but to bring
him back in, which I did. She referred me to a specialist. While waiting
for the specialist appointment in a few days, my baby boy started doing
strange things. He started arching his back and crying out in pain. He
was as stiff as a board. His eyes would roll into the back of his head.
He didn't have a temperature. He had also started shuddering but he
wasn't cold. (I later learnt from the doctor these were convulsions and
seizures). The vomiting continued and I was convinced to give up
breastfeeding by the clinic sister. He vomited up the formula also. I
was getting very scared.

Messenger
doesn't say why she thought the vaccines had made her infant sick. She
may have been influenced by the anti-vaccination movement in Australia
and elsewhere. She may have been influenced by seeing Dr. Robert S. Mendelsohn on the Phil Donahue show talking about the dangers of vaccination.
In any case, her early judgment that vaccines caused her son's
convulsions and other problems was not based on scientific evidence. All
she knew for sure at that point was that the infant showed signs of illness shortly after his vaccinations. Whatever the trigger, her initial judgment about the cause of her son's seizures wasn't based on research she had done.
The research would come later. To her credit, she was skeptical of her
doctor's assurance that the connection between the vaccinations and the
convulsions was coincidental. She was not afraid to challenge the
medical community. She would not blindly accept what the health experts
had to say about the value and safety of vaccinations. She set out to do
her own research. That's an admirable trait and is to be commended.